ANCHORAGE, Alaska  North Pacific right whales may not be going extinct after all.

Scientists have found twice as many right whales in the Bering Sea as previously spotted, giving them hope the rare whales are making a comeback.

"We saw more right whales in the Bering Sea than have been documented in the last five years combined," said National Oceanic and Atmospheric Administration (NOAA) scientist Robert Pitman, who was aboard a research vessel that spotted 25 whales, including three cows with calves.

"It is definitely a reason for cautious optimism," Pitman said.

The NOAA scientists were conducting a survey of humpback whales last month when they spotted a right whale and followed it. The scientists decided to go to an area of the Bering Sea where whales had been seen before.

"As we were approaching the area, we found a couple of right whales and were extremely surprised to find a cow and a calf. This was only the second calf to be seen in the North Pacific in about 100 years," Pitman said.

"There are at least twice as many as previously thought," said NOAA scientist Paul Wade, who was involved in placing satellite tags on two whales in August. "It is very good news for this species."

Right whales in the Pacific and Atlantic oceans were hunted nearly to extinction before coming under international protection in 1949. The number in Alaska waters probably is in the dozens. More than 100 are in waters off Russia and Japan.

There were very few sightings of Pacific right whales from 1900 into the mid-1990s. Scientists were puzzled by the rarity of whale sightings in Alaska until finding out in 2000 that the Soviets had illegally harvested several hundred in the Bering Sea and south of Kodiak in the mid-1960s.

Many scientists considered the illegal harvest the death blow to the species. But in 1996, NOAA scientists found a small number of right whales foraging in an area of Bristol Bay.

"That was very much a surprise. Up until that time there was growing concern that the population may have been extinct or headed toward extinction," Pitman said.